The following description relates to a microscope with an adjustable stage.
A microscope is an optical instrument that uses a lens or a combination of lenses to produce magnified images of small objects, especially of objects too small to be seen by the unaided eye. Depending on the size of the object or the purpose for viewing the object, either microscopic or macroscopic viewing may be desirable. Microscopic viewing refers to viewing a microscopic specimen (a specimen that is not visible by the naked eye), or a microscopic portion of a macroscopic specimen, at relatively high magnification levels in a relatively small field of view. The lens or lenses used for microscopic viewing have short working distances, and the specimen is relatively close to an outermost lens. By contrast, macroscopic viewing refers to viewing a macroscopic specimen (a specimen that is visible by the naked eye) at relatively low magnification levels in a relatively larger field of view. The lens or lenses used for macroscopic viewing have longer working distances, and therefore larger specimens, for example, insects or rocks, may be viewed.
A conventional microscope providing a range of magnification levels may include multiple tubes including one or more lenses, the tubes mounted on a rotatable nosepiece, such that the lens or lenses within an optical path can be changed by rotating the nosepiece, thereby changing the magnification level. The more tubes included on a nosepiece, the heavier the microscope becomes. Additionally, the wider the range of magnification levels, the wider range of working distances required, and therefore the larger and heavier the microscope. Typically, fine and coarse adjustment mechanisms are provided to focus an image to be viewed through the microscope, which mechanisms may further adjust the working distance. Although the conventional microscope may provide a range of magnification levels, the magnification levels are all either for microscopic viewing or for macroscopic viewing, but not a combination of the two.
Another type of microscope, which provides a range of magnification levels for macroscopic viewing, includes a tumbler-style lens changer rotable about an axis that is substantially perpendicular to an optical path and including multiple lenses arranged radially about the axis, such that the tumbler is positionable into multiple positions to change the lens or lenses within the optical path, thereby changing the magnification level provided. The tumbler is located within a head that is movable within a relatively short distance relative to a stage, to provide different working distances for the different macroscopic magnification levels provided. Two such tumblers, or a duo-tumbler, are included in the head of the microscope, providing stereoscopic vision.
Microscopes are often used by students in an educational environment, such as a classroom, and may be used in the field, either by students or others, to examine specimens within their natural environment. The specimens to be viewed may range from live organisms to plant cells, requiring a wide range of magnification levels as well as both microscopic and macroscopic viewing. Having more than one type of microscope available to students, such as a microscope with macroscopic magnification levels and a second microscope with microscopic magnification levels, may be cost prohibitive. Further, it may be impractical for a user to carry two different microscopes into the field, when examining a wide range of specimens.